Finite-range interactions and phases

Summary

We consider a one-dimensional system of hard balls on the positive half-line with a general finite-range interaction in thermodynamical equilibrium. We show that, under the action of a weak gravitational field, one can distinguish two spatially separated subsystems: a dense one, which we call the condensate, and a dilute one which we call the gas; between these two, there is a narrow interface where both subsystems mix.